Abstract: A wall brace apparatus and method for holding together and supporting walls and also for forming an arena or walled enclosed structure. Wall brace 10 or 15 has a frame 30, a top bracing member 40, and a bottom bracing member 50 for holding together, bracing, and supporting respective top sides and respective bottom sides of walls 60 adjacently to and in alignment with each other. Wall braces 10 or 15 are used to hold walls 60 to form side walls, and walls 60 can be easily assembled and disassembled from the top and bottom bracing members 40 and 50. Wall brace 20 or 25 also has a frame 30, a top bracing member 45, and a bottom bracing member 55 for holding together, bracing, and supporting respective sides of walls 60 at an angle to each other. Wall braces 20 or 25 are used to hold walls 60 to form corner walls, and the walls 60 can also be easily assembled and disassembled from the top and bottom bracing members 45 and 55.